Bulletin of the American Physical Society
2005 14th APS Topical Conference on Shock Compression of Condensed Matter
Sunday–Friday, July 31–August 5 2005; Baltimore, MD
Session T1: Energetic Materials VI |
Hide Abstracts |
Chair: Harold Sandusky, Naval Surface Warfare Center, Indian Head Room: Hyatt Regency Constellation B |
Thursday, August 4, 2005 1:00PM - 1:15PM |
T1.00001: Development of a Mechanistic Burn Modeling of High-Explosives Yuichiro Hamate, Yasuyuki Horie This paper describes a new computational framework for reactive burn modeling of solid explosives and proof-of-concept calculations. Our goal is to expand predictive capability through inclusion of various micro-mechanical burn processes. We propose a model which is complicated enough to represent underlying physics, but simple enough for engineering scale computations. Key components of the model include energy localization, the growth of hot spots, micro-mechanics in/around hot spots, and a phase-averaged mixture equation of state (EOS). The nucleation and growth of locally heated regions is treated by a statistical model based on an exponential size distribution. Proof-of-concept calculations are limited to shock loading, but show the capability of simulating Pop-plots, initial temperature effects, curved detonation waves in 2D, sandwich tests, and multi-dimensional effects, in a unified fashion based on micro-physics. [Preview Abstract] |
Thursday, August 4, 2005 1:15PM - 1:30PM |
T1.00002: Numerical Study of Mechanism of Hot Spot Formation in Heterogeneous HE. Vladimir Klimenko To prepare a precise numerical model of detonation it is necessary to use perfect physics for description of multiple detonation process. Hot spot mechanism is used (in different numerical realizations) in all current numerical detonation models. All previous investigations of this process were concerned to pressure region 10-30 kbar. But, real calculations deal with more wide range 10-500 kbar. We have studied physics of hot spot formation process at pressures 30-150 kbar. Detailed study was made by 2D hydrocode with including a viscous heating as key mechanism of energy dissipation in hot spot process. We considered real case, namely, ignition of pores in PBX-9501 with specific distribution in size. Process of hot spot formation has three stages: (1) quasi-thermal explosion,(2) transition stage and (3) stage of steady burning. Only the first stage is realized for small pores at low pressures. This gives dramatic change in burning topology of real HE compositions when pressure crosses transition region 60-80 bar. Obtained results on hot spot mechanism have permitted to improve greatly physical level of numerical model of detonation. [Preview Abstract] |
Thursday, August 4, 2005 1:30PM - 1:45PM |
T1.00003: Burning Crack Networks in Cook-off Explosions Larry Hill Burning crack networks can play an important role in cook-off explosions. Combustion gases create pressure, pressure accelerates reaction, and the process runs away. The reaction rate increases with {\it crack stiffness}, characterized by the pressure required to increase its width. A crack's stiffness is increased by its burning neighbors, which push against it and oppose its growth. I present a simple analysis of this effect, and couple to it a simple burning model to show approximately how combustion runs away. The model compares favorably with the mechanically-confined cook-off experiments of Dickson et al. [1]. [1] Dickson PM, Asay BW, Henson BF, & Smilowitz LB (2004) Thermal cook-off response of confined PBX 9501, {\it Proc. R. Soc. Lond. A pp. 3447-3455} [Preview Abstract] |
Thursday, August 4, 2005 1:45PM - 2:00PM |
T1.00004: Progress in the analysis of the Forest Fire model. Shirish Chitanvis Asymptotic analysis underlying Bdzil's Detonation Shock Dynamics (DSD) theory is used to obtain mesh-independent results for the Forest Fire burn model. Using the published burn rate for PBX 9501 as given by the Forest Fire model, and standard mixture rules for the products (pressure and temperature equilibrium), we obtain a D$_{n}-\kappa $ relation for PBX 9501. It provides a reasonable estimate for the failure diameter for PBX 9501. However, the deficit is extremely small even in the vicinity fo failure I.e., (D$_{CJ}$- D$_{n}$-)/D$_{CJ} \quad \sim $ O(10$^{-4})$, where D$_{CJ}$is the Chapman-Jouguet (CJ) detonation speed when compared to experimental results. It is pointed out that ameliorating the Forest Fire burn rate at pressures above 100 kbars leads to much improved results for the D$_{n}-\kappa $ curve. [Preview Abstract] |
Thursday, August 4, 2005 2:00PM - 2:15PM |
T1.00005: New Aspects of Physical Kinetics Franklin E. Walker (A) A short review of Physical Kinetics principles (B) A statement and details regarding the Controlled Production of Nuclear Fusion Energy by Collisional Activation. (C) A statement and details regarding a new Thermonuclear Detonator and discussion of its applications. (D) Affidavits from scientists qualified to comment on this work. (E) A presentation of a method for developing fusion energy from water---via hydrogen. (F) A short presentation of the nomination for the Nobel Prize for Chemistry for some of this work. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700